The art of perfumery, having its origins in antiquity, has until very recent times relied predominantly on natural perfume essence oils for its pallette. Rapidly expanding population in modern times with concomitant changes in economic patterns and land use have made an unfavorable environment for the cultivation of essential oil crops. This has resulted in an increasingly sporadic, uneconomic, and insufficient supply of natural fragrance oils. As a result, the modern perfumer has devoted much of his time to replacing natural materials with synthesized raw materials which can be produced in both consistent quality and controllable cost from petrochemicals.
An aspect which has presented a problem to the perfumers while using synthetic raw materials is that of duplicating the rounded (blended) and full bodied effect of natural essential oils. These materials are normally quite complex with respect to trace ingredients which more often than not make important contributions to the odor profile, augmenting the odor strength, and blending the odor profile of the constituents. Accordingly, there is a continued search, which is especially evident within the last decade, for materials of unique odor character which can lend novel effects to modern perfumes and provide "lift" and strength enhancement sought with perfumes containing dominant proportions of petrochemically based raw materials.
One source of such petrochemically based raw materials is isobutylene having the structure: ##STR5## which in its conversion to fuel products gives rise to side products which are trimers, commonly called "triisobutylene" but which have structures defined according to the generic structures: ##STR6## wherein each of the generic structures set forth above, in each of the molecules, one of the dashed lines represents a carbon-carbon double bond and each of the other of the dashed lines represent carbon-carbon single bonds.
The instant invention relates to reacting one or more of these "triisobutylene" derivatives which are produced by trimerization of isobutylene having the structure: ##STR7## with an acylating agent, more particularly with an acyl anhydride defined according to the generic structure: ##STR8## where R.sub.1 and R.sub.2 are the same or different and each represents methyl or ethyl.
The use of petroleum feedstocks as precusors for producing perfumery products is known in the prior art.
Thus, for example, U.S. Pat. No. 4,219,450 issued on Aug. 26, 1980 discloses the utilization of oximes of propene trimers and propene tetramers for augmenting or enhancing the aromas of colognes, perfumes and perfumed articles including detergents and cosmetics. It is indicated that these propene trimers are defined according to the structure: ##STR9## wherein R.sub.1 ' R.sub.2 ' R.sub.3 ' and R.sub.4 ' represent hydrogen or aliphatic hydrocarbon articles having from 1 up to 7 carbon atoms with the total number of carbon atoms among R.sub.1 ', R.sub.2 ', R.sub.3 ', and R.sub.4 ' being 7 or being 10 (the 7 in a case of a propane trimer and the 10 being in the case of a propane tetramer. However, the propane trimer and the propane tetramer oximes of U.S. Pat. No. 4,219,450 are indicated to be produced in a rather complex manner by first forming the propane trimer or propane tetramer epoxide; then reacting the resulting epoxide with activated clay to rearrange same to produce the propane trimer or propane tetramer ketone; and finally reacting the resulting ketone with hydroxylamine hydrochloride to produce the propane trimer or propane tetramer oxime. Indeed the creation of the propane trimer or propane tetramer epoxide requires the use of proxy compounds such as peracetic acid. Both the oximation step and the epoxidation step require great care in view of the danger of explosions capable of occurring during these processing steps.
Unsaturated ketones including unsaturated branched aliphatic acyclic ketones are well known for use for augmenting or enhancing the aroma and/or taste of consumable materials. Thus, Arctander, "Perfume & Flavor Chemicals (Aroma Chemicals)", published 1969, discloses at monograph No. 472, the use of butylidene acetone having the structure: ##STR10## Arctander states that butylidene acetone has a powerful, grassy, green pungent odor and a rather poor tenacity. At monograph 2427, Vol. 2 Arctander states that Octylidene acetone having the structure: ##STR11## is useful in Jasmin compositions as a modifier for Amylcinnamic aldehyde, or in Gardenia and other heavy floral perfumes, where herbaceous-fruity notes are desirable and compatible with the fragrance picture.
U.S. Pat. No. 2,315,046 discloses the use as ingredients in perfumery of certain acylated olefins, which olefins have structures such as: ##STR12##
These materials are prepared interalia from commercial diisobutylene according to the reaction: ##STR13## wherein n is 3 or more, and R represents a hydrocarbon radical. radical. Branched unsaturated alpha-beta ketones were known prior to that, for example in U.S. Pat. No. 2,246,032, issued on June 17, 1941, disclosing compounds having the generic structure: ##STR14## wherein R.sub.1 -R.sub.7 may be any member of a group consisting of hydrogen, aliphatic and cyclo praffinic.
Also claimed in U.S. Pat. No. 2,315,046 are compounds having the structure: ##STR15##
In addition, U.S. Pat. No. 2,463,742 discloses the reaction: ##STR16##
U.S. Pat. No. 3,453,317, issued on July 1, 1969, discloses certain gamma, delta unsaturated ketones as odorants for perfumery purposes at Column 4, line 33 including the group of ketones having the structures: ##STR17## wherein R.sub.1 -R.sub.5 are various hydrocarbon radicals.
U.S. Pat. No. 2,870,210, discloses as having aromas such as fruity, "reminiscent of apple juice" the compound 6,8-dimethyl-5-nonene-2-one having the structure: ##STR18## as well as 6,10-dimethyl-5-undecane-2-one having the structure: ##STR19##
Since approximately 1960, International Flavors & Fragrances Inc. has been utilizing reaction products of acetic anhydride and triisobutylene in perfumery wherein the reaction takes place using a polyphosphoric acid catalyst. The preparation of the reaction product of acetic anhydride and triisobutylene in the presence of polyphosphoric acid is specifically set forth in Example "B", infra.
In comparing the organoleptic properties of the products prepared by reacting acetic anhydride with triisobutylene in the presence of polyphosphoric acid is the products prepared by reacting acetic or proprionic anhydride with triisobutylene in the presence of a Lewis acid catalyst, it is evident that the properties of the different materials are unexpectedly different from one another with each of the materials having their own specific advantages, depending upon whether the Lewis acid or protonic acid catalyst is used. Indeed as will be seen in the section entitled "Brief Description Of The Drawings", infra, the GLC profiles for the materials prepared using the Lewis acid catalyst in comparison to the materials prepared using the Lewis acid catalyst are quite different.